AI 中文总结
本研究针对FLASH放疗生物选择性物理起源未明的问题，构建扩散-吸收模型，发现非线性吸收可减少周围未暴露区域能量吸收，其效应与FLASH放疗的组织保护作用相似，结果表明需匹配能量沉积条件与材料吸收特性。
AI 中文摘要
肿瘤的FLASH放疗已被证实能高效保护正常组织，但其生物选择性的物理起源尚未阐明。本研究构建了极简扩散-吸收模型，以探究非线性能量吸收对类FLASH沉积过程中能量空间分布的影响。模拟显示，非线性吸收会改变能量在系统中的传递，同时减少周围未暴露区域吸收的能量，该行为在性质上与FLASH放疗中观察到的组织保护效应相似。参数空间分析表明，入射脉冲强度的影响取决于材料的吸收特性，包括其饱和行为和能量阈值。这些结果表明，能量沉积条件应与目标材料的吸收特性相匹配。
英文摘要
FLASH radiotherapy for tumors has proven highly effective in preserving normal tissue; however, the physical origin of its biological selectivity has yet to be elucidated. This study developed a minimal diffusion-absorption model to examine the effects of nonlinear energy absorption on the spatial distribution of energy during FLASH-like deposition. Simulations revealed that nonlinear absorption alters the transfer of energy through the system while reducing the amount of energy absorbed in surrounding, unexposed regions. This behavior qualitatively resembles the tissue-sparing effect observed in FLASH radiotherapy. Parameter-space analysis revealed that the effect of incident pulse intensity depends on the absorption properties of the material, including its saturation behavior and energy threshold. These results suggest that energy-deposition conditions should be matched to the absorption characteristics of the target material.
